# 'Mathematics of life'

### review by Adam Kucharski

## Mathematics of life: Unlocking the secrets of existence

### By Ian Stewart

Mathematicians and physicists have long fought over the big names. Newton? He was one of us, the physicists claim, with his studies of gravity, light and motion. But he invented calculus, the mathematicians reply, he worked on geometry and harmonic series. And what about Stokes, Dirac and Einstein – were they motivated by the abstract ideas of mathematics or the natural wonders of physics?

If a rapidly developing trend continues, mathematicians and biologists may soon be having similar arguments. Ian Stewart's latest book guides us through the recent collision of these two fields. This is not a book about mathematics with a bit of biology sprinkled on afterwards – *Mathematics of life* weaves a history of biology with examples of how mathematics can help solve the unanswered questions that were created along the way. Mathematics, Stewart argues, will be the next biological revolution.

In fact it's already happening. In the last couple of decades mathematicians have increasingly become involved in everything from ecology to genetics – the tools at their disposal a valuable addition to existing biological methods. Science is evolving, with new levels of cooperation allowing us to do things that were once unachievable.

Of course, mathematical biology covers a bewilderingly large variety of research. Many of these topics would fill books on their own, so instead Stewart gives us an overview of a few key research areas over the course of nineteen chapters. Well-chosen illustrations allow the reader to get their head around the biological background, and analogies are provided to help them understand the systems that mathematicians are working to explain. The topics covered are wide ranging: how symmetry plays a role in virus structure, the split of a single species into two and even animal coat patterns; why game theory – famously used in *A beautiful mind* to ensure that everyone gets a date – can help find out which evolutionary strategies are best; what problems in genetics, a field that often finds itself in the news, can be understood using probability.

Stewart is a stalwart of the popular maths genre, having previously written accounts of mathematical subjects as diverse as chaos theory, symmetry and probability, and his engaging, accessible style is also present here. In fact, this book doesn't contain much mathematics in the shape of formulae and calculations, but this is precisely Stewart's point about mathematical biology – the puzzles should come from the biologists, rather than biology just being another area of application for existing mathematical results. It is a story of how scientists with contrasting backgrounds are coming together to solve real-life problems – important work that, in my opinion, cannot be emphasised enough.

As well an author, Stewart is also a researcher, and his work on how animals walk inevitably gets a mention, sandwiched between sections on the brain and leech heartbeats. The book's breadth, ambitiously aiming to give the reader a gist of many different corners of such a big research field, makes it an interesting read but inevitably creates a weakness too – many topics are omitted or mentioned only too briefly. However, by including a solid biological backdrop for the problems he does cover, Stewart gives the book a nicely rounded feel, even if some chapters leave the reader wanting more. As an overview, it provides an entertaining and up-to-date insight into this exciting field.

Despite its title, this is a book for fans of biology as much as for those interested in mathematics. In many ways it reflects the increasingly blurred boundaries between the two subjects (I know mathematicians that work in zoology departments, medical schools and even for government health agencies), and gives an absorbing introduction to one of the fastest growing areas of modern science. According to Aristotle, "in all things of nature there is something of the marvellous". Now mathematics can help us find it.

**Book details:***Mathematics of life: Unlocking the secrets of existence*- Ian Stewart
- hardback — 368 pages
- Profile Books (2011)
- ISBN: 978-1846681981

### About the author

Adam Kucharski is a PhD student in applied mathematics at the University of Cambridge. His research covers the dynamics of infectious diseases, focusing on influenza in particular.